Yet another Exchange 2010 Management Tools error case, with the error: The WinRM client cannot process the request. It cannot determine the content type of the HTTP response from the destination computer.
In this case, all of the troubleshooting used to resolve the issue previously (see my post http://blogs.technet.com/b/richardroddy/archive/2010/06/29/exchange-2010-management-tools-error.aspx) had been done and we were still getting the errors.
In this case, the issue did come back to the web.config file(s) again. For this customer, redirection was enabled for the Default Web Site to send it to the OWA path), which when done through the IIS Management Console, enables it for all sub-directories under the web site. Even after turning the redirection off for the Powershell virutal directory in the IIS interface, we still had problems.
I ended up tracking this one down to the web.config file in the Powershell virtual directory. In the web.config, we had sections for <httpErrors> and <httpRedirect> (although it was set to false). We removed these sections from the file and then we could use the Exchange Management Tools again.
So, among the list of things to check if you’re running into these errors, along with the information in http://msexchangeteam.com/archive/2010/02/04/453946.aspx, see if you have <httpRedirect> or <httpErrors> sections in the web.config file in the Powershell. If so, delete them.